A flash‐evaporation scheme modified to control the rate of the powder fed to the evaporator was used for depositing GaAs films on amorphous glass substrates. A bulk wurtzite form of GaAs was identified with x‐ray diffraction and found to have an axial ratio of 1.684. Periodic faulting induced by the plunger movement of the powder feeder is believed to cause the formation of this phase. Structural analysis of the flash evaporated films was performed using a Fourier line broadening analysis and integral breadth measurements. A least‐squares approximation of the ``Warren‐Averbach'' method yielded particle sizes of 125 Å and rms microstrains of 0.0018. The films were doped during growth with germanium, indium and tin. Germanium doping producedp‐type films while both indium and tin doping producedn‐type. Mobilities greater than 0.5 cm2/V·sec were found for a narrow range of doping (1018−1019/cm3) for the tin doped films. The films grown with no auxiliary dopant werep‐type with carrier concentrations exceeding 1019/cm3and mobilities near 0.01 cm2/V·sec.